Diagnostic kits and methods for diagnosis of axial pain with or without radiculopathy

ABSTRACT

The invention provides kits developed to analyze ex vivo, a sample retrieved from the area of the pathological condition for diagnosis and monitoring the pain generator(s) of axial pain with or without radiculopathy and methods for screening therapeutic compounds potentially useful for treating axial pain with or without radiculopathy. Alternatively, degenerated discs can be monitored and treated before occurrence of a pathological pain condition. Pain markers and markers of degenerating disc include markers of neuronal, vascular, immune and matrix elements.

FIELD OF THE INVENTION

This invention relates to diagnostic kits and methods useful fordiagnosis and monitoring the pain generator(s) of axial pain with orwithout radiculopathy and methods for screening test compoundspotentially useful for treating axial pain with or withoutradiculopathy.

BACKGROUND

The spine is a remarkably strong and flexible structure that is capableof withstanding substantial forces. A spine is formed from a pluralityof vertebrae, each of which is individually separated from the other bya disc. The discs are anterior to the spinal cord, which runs throughthe spinal canal of the vertebrae. The discs have several functions, oneof which includes serving as shock absorbers for the vertebrae.

Each disc has a relatively tough outer layer called the annulus fibrosusthat surrounds a gel-like inner layer called the nucleus pulposus. Theannulus fibrosis is composed of concentric layers of intertwined annularbands, which are arranged to resist forces placed upon the spine. Thecartilaginous endplate separates the nucleus pulposus and annulusfibrosus from the adjacent vertebrae. The posterior longitudinalligament strongly attaches to the annulus fibrosus. The nucleus pulposusis composed of cells from the primitive notochord in childhood andchondrocyte-like cells in adulthood, and contains significant amounts ofsubstances capable of exciting, or increasing the excitability of,sensory nerves. These substances include prostaglandin E, histamine-likesubstances, potassium ions, lactic acid, and several polypeptide amines.

Pain arising from the disc or elements adjacent to an intervertebraldisc may cause axial pain also called discogenic pain with or without aradiculopathy component. Generally, though not always, to experiencepain in a particular region the presence of nerve endings in that regionis required. One source of pain is caused by the activation of specificnociceptors connected with C- and A-delta fibers. Another source of paininvolves injury to sensory fibers, or damage to the central nervoussystem. Alternatively, abnormal interactions between neuronal extensionsof sensory and autonomic nature can also be involved in symptomaticpain. Hence, the innervation of the disc and elements adjacent to anintervertebral disc is of interest to the study of discogenic pain.

Neuronal extensions innervating the disc and region adjacent to the discare of motor, sensory or autonomic nature. Normal discs are rarelyinnervated deeper than the outer third of the annulus fibrosus. However,there are indications that degenerating or problematic discs have nerveextensions that extend centripetally beyond the outer third of theannulus fibrosis, reaching as far as the inner third of the annulusfibrosis, or even into the nucleus pulposus. The invasion of suchneuronal extensions may be a source of pain, particularly if they comeinto contact with those substances in the nucleus pulposus that arecapable of exciting such neuronal extensions. Signs of degenerationassociated with the development of axial pain with or withoutradiculopathy such as increasing innervation have also been found inelements adjacent to the disc, for example the endplates.

Discs are generally avascular, with the transport of nutrients andmetabolites occurring primarily through diffusion. However,degenerations tend to be more vascular than normal discs. Thiscentripetally invasive vascularization of the disc, analogous to theneuronal invasion, may contain a perivascular nerve network withvasomotor or vasosensory functionalities. Further, increasedvascularization of the disc is associated with increased innervation,and hence increased chances for discogenic pain.

A degenerating disc can be a contained disc or a herniated disc andcause discogenic pain also referred to as axial pain with or withoutradiculopathy. Herniation could be of a contained nature, for example,bulging of the disc. A herniated disc can also be ruptured with releaseof discal elements, such as the nucleus pulposus, outside the disc. Adegenerating disc can affect the surrounding neuronal elements includingthe spinal nerve roots and cause radicular pain or radiculopathy.Radiculopathy also referred to sciatica or arm or leg pain depending onthe level of the spine affected by the degeneration.

Changes in the appearance of the degenerating disc and/or elementsadjacent to the disc can be associated with changes in matrix componentsincluding changes in density such as increased density of the nucleuspulposus, level and type of extracellular matrix components such asproteoglycans, metalloproteinases and proteolytic enzymes, collagen andfibronectin fragments and content in nitric oxide and free radicals.

Immune elements including pro-inflammatory agents including cytokines,chemokines, growth factors, peptides, polypeptides and nitric oxidesynthetase can also be involved in the degenerative process anddevelopment of symptomatic pain associated with axial pain with orwithout radiculopathy clinical conditions.

In a Gallup Survey, 42% of American adults said that they experiencedpain on a daily basis. Amongst such sufferers of chronic pain,spine-related problems constitute the bulk of the complaints. Back andleg pain has been estimated to exist in as much as 66% of the generalpopulation. Beyond the substantial discomfort that back and leg paininflicts upon individuals, spine-related pain also incurs heavy socialcosts. For example, as many as one million spine surgeries, and as manyas five million interventional procedures, are estimated to be performedin the United States each year. Well beyond the purely medical andpsychological burdens of such procedures, the subsequent social costsrelated to productivity, disability compensation, and lost taxes, aresubstantial.

Accordingly, better strategies to diagnose the precise location of thepain generator(s) involved in axial pain conditions with or withoutradiculopathy are needed in order to increase the effectiveness oftherapeutic interventions.

In addition, better strategies to monitor the progression ofpathological changes in the disc or adjacent to an intervertebral discare needed to enable prophylactic treatment before the development of apainful condition.

SUMMARY OF THE INVENTION

The current invention fulfills this and other foregoing needs byproviding devices, methods, and compositions useful for diagnosis andmonitoring the pain generator(s) and markers of degeneration involved inaxial pain conditions with or without radiculopathy and methods forscreening therapeutic compounds potentially useful for treating theseconditions.

In one aspect, the invention provides a device for diagnosing andmonitoring the pain generator(s) and marker(s) of degeneration involvedin axial pain conditions with or without radiculopathy, comprising adetector for measuring an amount of a pain marker or a marker of discdegeneration, the detector comprising a sensing area, wherein thesensing area is at least partially insertable inside of or adjacent toan intervertebral disc. In another embodiment, the device furthercomprises a processor, operably connected to the detector and a displayoperably connected to the processor.

In another aspect, the invention provides a method of diagnosing andmonitoring the pain generator(s) and marker(s) or degeneration involvedin axial pain conditions with or without radiculopathy, in a patientcomprising determining an amount of a pain marker or a marker ofdegeneration, in a location inside of or adjacent to an intervertebraldisc; comparing the amount of the pain marker or marker of degeneration,from the patient with the normal range of the marker in a correspondinglocation, wherein the amount of the pain marker or marker ofdegeneration, outside of the normal range indicates a current or apotential pain generator. In one embodiment, the amount of pain markeror marker of degeneration, is evaluated by using a device that includesa detector. In another embodiment, the amount of pain marker or markerof degeneration, is evaluated by imaging techniques includingradiography, MRI, PET or SPECT, CT, fluoroscopy, luminescence and anycombination thereof. In another embodiment, the amount of a pain markeror marker of degeneration is measured in a sample retrieved from thedisc or from elements adjacent to the disc and analyzed ex vivo.

In different embodiments of the invention, the pain marker or marker ofdisc degeneration comprises a compound selected from the groupconsisting of markers of neuronal, immune, vascular and matrix elements,and any combination thereof.

More particularly, the pain marker or marker of degeneration can be amarker of neuronal element and selected from the group consisting ofneurotoxins, for example, a dye, neuronal growth factors including nervegrowth factor, brain-derived growth factor, glial-derived growth factor,neurotrophin-3, neurotrophin-4, insulin-growth factor, fibroblast growthfactor and leukemia inhibitory factor, extra-cellular matrix componentsincluding chondroitin sulfate proteglycans, netrins, semaphorins andmyelin/oligodendrocyte growth inhibitors, such as Nogo, MAG and Omgp,cell adhesion molecules, such as NCAM, N-cadherins and integrins, acytoskeletal element of the growth cone or neurofilaments, agents thatcan desensitize neuronal elements such as camphor, menthol, piperine,mustard oil, curcumin and eugenol and vanilloid receptor agonists andantagonists such as 8-Methyl-N-vanillyl-trans-6-nonenamide (Capsaicin);Z-Capsaicin; Gingerol; Zingerone; 8-Methyl-N-vanillylnonanamide(Dihydrocapsaicin);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-daphnetoxin,20-(4-hydroxy-5-iodo-3-methoxybenzeneacetate) (5′-Iodoresiniferatoxin);(+)-Isovelleral; N-Vannilyloleoylamide (Olvanil); Phorbol12,13-dinonanoate 20-homovanillate; Resiniferatoxin;N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);2,3,4-Trihydroxy-6-methyl-5-[(2E,6E)-3,7,11-trimethyl-2,6,10-dodecatrienyl]benzaldehyde (Scutigeral);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-20-(4-hydroxybenzeneacetate)daphnetoxin(Tinyatoxin); capsaicin synthetics; and capsaicin derivatives andvanilloid receptor antagonist such asN-[2-(4-Chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamide(Capsazepine);[N-(4-Hydroxy-3-methoxyphenyl)methyl]-5Z,8Z,11Z,14Z-eicosatetraenamide](Arvanil); N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791) and5′-iodoresiniferatoxin, agents that can reveal the presence and levelsof neuronal receptors and related ligands and molecules involved intrafficking, breakdown and recycling of the ligands and receptorsincluding nociceptors, adrenergic, cholinergic, glutamate, GABA,serotonine, somatostatin opioids, ATP, Na⁺, K⁺, Ca²⁺, cannabinoids,Substance P and neuropeptide receptors such exemplary agents may includeacetylcholine, acetylcholinesterase glutamate, adrenaline, epinephrine,botulinum toxin, anti-convulsants, anesthetics, analgesics, opioids andcannabinoids, agents that can detect neuronal supporting cells or glialcells including astrocyte, oligodendrocyte, microglia and Schawnn cellsmarkers such as Glial Fibrillary Acidic Protein, S-100, CR3 receptor andglial toxins such as fluorocitrate and any combinations thereof.

In different embodiments of the invention, the pain marker or marker ofdegeneration is an marker of immune element and selected from the groupconsisting of inflammation-linked cytokines, chemokines, potassium ions,lactic acid, neuropeptides and several polypeptide amines, bradykinin,histamine, prostaglandins ligands and related receptors and moleculesinvolved in trafficking, breakdown and recycling of ligands andreceptors including, without limitation IL-1, IL-6, IL-8, IL-10,TNF-alpha, INF and IFN regulatory factor 3, nitric oxide synthetase,Toll-like receptor and adaptor molecules and agents that can interactwith immune elements such as steroids, nonsteroidal anti-inflammatorydrugs, COX inhibitors, NFkB modulators and any combinations thereof.

In different embodiments of the invention, the pain marker or marker ofdegeneration is a marker of vascular element and selected from the groupconsisting of angiogenic and antiangiogenic ligands and relatedreceptors and molecules involved in trafficking, breakdown and recyclingof ligands and receptors including anti-angiogenic steroid or anangiostatic steroid, such as anecortave acetate or triamcinoloneacetonide, growth factor or cytokine such as vascular growth factor,fibroblast-growth factor, angiopoietins, pigment epithelium-derivedfactor or α-IFN, vascular extra-cellular matrix components includingMatrix metalloproteinase and modulators including marimastat, a vascularcell adhesion molecule such as a cadherin or integrin, marker ofvascular elements such as Von Willebrand factor and any combinationsthereof.

In different embodiments of the invention, the pain marker or marker ofdegeneration is a marker of matrix element including tissue density of,for example, the normally gel-like nucleus pulposus, level and type ofextracellular matrix components such as proteoglycans,metalloproteinases and proteolytic enzymes, keratin sulfate, collagen,fibronectin fragments, free radicals, nitric oxide, and any combinationsthereof.

In other embodiments of the invention, the pain marker or marker ofdegeneration may comprise a physical activity or a physical stimulus,such as, for example, pressure, neuronal electrical activity, thermalchanges, pH, water content, tissue density, absorption ofelectromagnetic radiation, and any combination thereof.

In other embodiments of the invention, the pain marker or marker ofdegeneration is a neuronal, immune, vascular or marker of matrix elementthat has been modified so it can be used with imaging techniquesincluding radiography, MRI, PET or SPECT, CT, fluoroscopy, luminescenceand any combination thereof. More specifically, neuronal, immune,vascular or marker of matrix element can be linked to a radioisotope,such as, for example, ¹⁸F, ³H, ¹²⁴I, ¹²⁵I, ¹³¹I, ³⁵S, ¹⁴C, ¹¹C or afluorescent molecule. Exemplary agents include modified agents that canbind opioid receptors such as ¹⁸F1-(3-fluoropropyl)-4-(4-cyanophenoxymethyl)piperidine or [(18)F]FPS or¹⁸F-FPS, ³H and ¹¹C carfentanil, ³H pentazocine, ³H-1,3di-ortho-tolylguanidine, (+)-p-¹¹C methylvesamicol, ¹¹C SA4503, ¹¹CSA5845, N-[¹⁸F]4′-fluorobenzylpiperidin-4yl-(2-fluorophenyl)acetamide([18F]FBFPA),3-(4-chlorobenzyl)-8-[¹¹C]methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one,¹¹C nemonapride, radiolabeled pentazocine, progesterone, SKF10,047,DuP734, BD1008, SM-21, haloperidol, DTG, progesterone, modified agentsthat can bind glutamate receptor ³H MK801,1-amino-3-[¹⁸F]fluoromethyl-5-methyl-adamantane, ¹¹C-ABP688, modifiedagents that can detect cholinergic receptor and transmission such as[¹⁸F]fluoroethoxy-benzovesamicol, 2-[¹⁸F]F-A-85380, [¹¹C]-mecamylamine,5-(3′-fluoropropyl)-3-(2-(S)-pyrrolidinylmethoxy)pyridine (nifrolidine),5-(2-(4-pyridinyl)vinyl)-6-chloro-3-(1-methyl-2-(S)-pyrrolidinylmethoxy)pyridine,[N-¹¹C-methyl]-benztropine neuronal glial marker such as molecules thatcan bind to the peripheral benzodiazepine receptor including¹¹C-R-PK11195, a radiolabeled antibody such as a radiolabeled antibodythat can bind the marker of matrix element, keratin sulfate.

In another aspect, the invention provides a method of testing an abilityof a treatment comprising administering a therapeutic compound to reducethe intensity of the signal derived from the pain marker of marker ofdegeneration, the method comprising: determining an amount of a painmarker or marker of degeneration in a location inside of or adjacent toan intervertebral disc at a first time, said first time is prior to afirst administration of the therapeutic compound; determining an amountof the pain marker or marker of degeneration in the location inside ofor adjacent to the intervertebral disc at a second, later time; whereby|M₁−N|>|M₂−N| indicates that the treatment is efficient in reducingaxial pain with or without radiculopathy or the likelihood thereof inthe future, wherein M₁ equals to the amount of the pain marker measuredat the first time; M₂ equals to the amount of the pain marker or markerof degeneration measured at the second time; and N equals to the normalrange or amount of the pain marker or marker of degeneration. Indifferent embodiments of the invention, the treatment comprises theidentity of the therapeutic compound, the combination of the therapeuticcompounds, the dosage of the therapeutic compounds, and other variablesof treatment.

In yet another aspect, the invention provides a method of monitoringaxial pain with or without radiculopathy or a likelihood thereof in afuture, comprising: determining an amount of a pain marker or marker ofdegeneration in a location inside of or adjacent to an intervertebraldisc at a first time; determining an amount of the pain marker or markerof degeneration in the location inside of or adjacent to theintervertebral disc at a second, later time; whereby |M₁−N|<|M₂−N|indicates that axial pain with or without radiculopathy or thelikelihood thereof in the future has increased, and |M₁−N|>|M₂−N|indicates that pain or the likelihood thereof in the future hasdecreased, wherein M₁ equals to the amount of the pain marker or markerof degeneration measured at the first time; M₂ equals to the amount ofthe pain marker measured at the second time; and N equals to the normalrange or amount of the pain marker or marker of degeneration.

In another aspect, the invention provides a provocative test aiming atincreasing, directly or indirectly, the signal derived from the painmarker or marker of degeneration in order to improve the sensitivity ofthe detection method comprising: administration of the pain marker ormarker of degeneration, administration of an activator followed by thedetection process. Alternatively, the activator can be administeredprior or concurrently to the pain marker or marker of the degeneration.The activator could be of a chemical, biological or physical nature.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 illustrates one embodiment of a device of the present invention.

DETAILED DESCRIPTION

The present invention provides devices, methods, and compositions usefulfor diagnosis and monitoring of discogenic pain and methods forscreening therapeutic compounds potentially useful for treating axialpain with or without radiculopathy.

Definitions

To aid in the understanding of the invention, the following non-limitingdefinitions are provided:

The term “adjacent to” the disc means a location within the spinalcolumn.

The term “spinal column” includes neuronal, bony, vascular and softtissue components. This includes the vertebral bodies and all theirassociated joints (facets, costovertebral joints, and disc interfaces),the intervertebral discs, the intrinsic musculature, the spinal cord,spinal nerves, sympathetic nerves and ganglia associated with the axialskeleton, vertebral and disc innervations, and all associated bloodvessels.

The term “axial” refers to the head, neck and/or back of a subject.

The term “diagnostic” or “diagnosing” means identifying the presence,absence, and location of one or more pain generators or potential paingenerators associated with axial pain with or without radiculopathy.

The term “disc” may be any disc within a spinal column, includingcervical, thoracic and lumbar discs.

The term “disc region” is intended to include a region extending about 5cm from the surface of a disc, the surface of the disc, as well asinterior regions within the disc.

The term “degeneration” refers to anatomical signs of degeneration,which can include changes in the height of the disc, the level ofhydration of the disc, ruptured or contained herniation, annularbulging, the presence of tearing or osteophytes. A reduction in theheight of the disc may be one of the most common, early and easilydetectable changes present in a degenerating disc. Another sign ofdegeneration is normally loss of the T2 weighted signal on an MRI scan;this is indicative of a loss of hydration of the nuclear tissue. Thedegeneration can be a contained disc that occupies the space determinedby the size of the endplates or a herniated disc. Herniation could be ofa contained nature called, for example, bulging of the disc or aherniated disc can also be ruptured with release of discal elements,such as the nucleus pulposus, outside the disc. Signs of degenerationsuch as inflammation, tissue density, changes in pH, increasedinnervation and vascularization can also be found in elements adjacentto the disc.

The term “radiculopathy” refers to radicular leg or arm pain derivedfrom abnormalities of the disc or elements adjacent to the disc that canaffect a spinal root or other neuronal elements within the spinalcolumn.

The term “degeneration” refers to a traumatic or progressive abnormalitylinked to the development of an axial pain with and withoutradiculopathy condition. Suitable non-limiting examples of degenerationin the intervertebral disc or the area adjacent to the disc includebulging or protrusion, inflammation, pressure, changes in neuronal,vascular, immune or matrix elements, electrical activity, water content,tissue density, and pH.

The term “fragments” of a protein should be interpreted broadly andshould include the whole protein.

The term “inflammation-linked cytokines” refers to both pro-inflammatorycytokines, such as, for example, TNF-alpha, IL-1 and IL-8, andanti-inflammatory cytokines, such as, for example, IL-4 and IL-10. Insome situations, it may be more advantageous to quantifypro-inflammatory cytokines as they appear when an inflammation occurslocally and disappear quickly when the inflammation subsides. On theother hand, anti-inflammatory cytokines may be detected even after theinflammation has subsides. Igarashi et al., SPINE 29(19): 2091-2095(2004).

The term “neuronal element” includes a neuron body; extensions of aneuron, such as axons, axonal branches, dendrites or growth cones; andsupporting cells, such as glial cells including astrocytes, Schwanncells microglia and oligodendrocytes.

The term “vascular element” includes blood vessels, capillaries andendothelial cells.

The term “matrix element” refer to elements within the disc or adjacentto the disc that are not neuronal, vascular or immune elements.

The term “marker” refers to a chemical, biological or physical agentthat can, directly or indirectly, reveal the presence, the amount oractivity of a neuronal, vascular, immune or matrix element within thepain generator(s) or potential pain generator(s) associated with thedevelopment of axial pain with or without radiculopathy conditions.

The term “marker of degeneration” refers to a marker that can identify apotential pain generator within the disc or an element adjacent to thedisc that is associated with the development of future painfulconditions.

The term “pain marker” refers to a marker that can identify a paingenerator within the disc or an element adjacent to the disc andassociated with painful conditions.

The term “pain generator(s)” refers to the disc or elements adjacent tothe disc identified as key element(s) involved in painful conditions andrevealed by pain markers.

The term “potential pain generator(s)” refers to disc or elementsadjacent to the disc identified as key element(s) involved in conditionsthat may potentially become painful and revealed by markers ofdegeneration.

The term “activator” refers to a chemical, biological or physical agentthat can reveal, directly or indirectly, the presence of or improve thesignal derived from a pain marker or marker of degeneration within paingenerator(s) or potential pain generator(s) associated with developmentof axial pain with or without radiculopathy conditions.

The term “therapeutic compound” refers to a chemical, biological orphysical agent that can modulate a pain marker or marker ofdegeneration.

The term “modulate” refers to reducing the activity, concentration,number of or level of a marker or neuronal, vascular, immune or matrixelement.

The term “patient” includes a living organism belonging to the phylumChordata upon which the methods and/or devices of the current inventionis used. The term includes, without limitation, humans.

The term “practitioner” means a person who is using the methods and/ordevices of the current disclosure on the patient. This term includes,without limitation, doctors, other medical personnel, veterinarians, andscientists.

The terms “quantifying,” “determining quantity,” “determining anamount,” or determining a number” of a parameter includes determiningboth absolute values (e.g., meters, grams, moles) and relative values(e.g., relative light units or ratios compared to control values). Thiscan also be estimated or calculated values, wherein the level of oneitem is estimated or calculated based on a measured value.

The term “treating” or “treatment” of a disease refers to executing aprotocol, which may include administering one or more drugs or physicaltherapy activities or a surgical procedure to a patient (human orotherwise), in an effort to alleviate signs or symptoms of the disease.Alleviation can occur prior to signs or symptoms of the diseaseappearing, as well as after their appearance. Thus, “treating” or“treatment” includes “preventing” or “prevention” of disease. Inaddition, “treating” or “treatment” does not require completealleviation of signs or symptoms, does not require a cure, andspecifically includes protocols which have only a marginal effect on thepatient.

Device

In one aspect, the invention comprises a device for diagnosing axialpain with or without radiculopathy. In one embodiment, depicted in FIG.1, the device comprises a detector 5 for measuring an amount of a painmarker or marker of degeneration. The detector 5 is operably connectedto a processor 10. The processor 10 receives information from thedetector 5, analyzes this information, and sends it to a display 15 and,optionally, to an alarm 20.

In one embodiment of the invention, the detector 5 is in a shape of aneedle, which, in one embodiment, has a diameter of 18 G or less. Thedetector 5 at least partially can be inserted in the disc regionpercutaneously. If desired, the detector 5 may be implanted in a desiredlocation, e.g., in the disc region. It may be advantageous to providefor securing the detector 5 in its target location. Accordingly, in oneembodiment, the detector 5 further comprises anchors 25. In the depictedembodiment of the invention two anchors 25 are shown. A person ofordinary skill in the art, however, would recognize that the number ofanchors may be more or less than just two. All such modifications areexplicitly included in the scope of the current invention. In oneembodiment, the detector 5 may be delivered to the target location by acatheter or another insertion device. Preferred materials for thecatheter or the insertion device include stainless steel and other rigidcompositions. In some embodiments, the insertion device pointed and/orsharp at the tip to facilitate penetration of the skin of the patient.

The detector 5 further comprises a sensing area 30. The sensing area 30is the part of the detector 5, which has to be placed in the discregion. The sensing area 30 comes into contact with the pain marker ormarker of degeneration. Depending on a choice of the pain marker ormarker of degeneration, different mechanisms of sensing the amount ofthe pain marker or marker of degeneration are possible. These mechanismswill be discussed below in connection with a discussion of the painmarker or marker of degeneration.

The processor 10 receives the signals from the detector 5, processesthese signals, and sends the processed information to the display 15.Depending on an embodiment of choice, the processor 10 may also bepercutaneously inserted or implanted into a patient with the detector 5.In other embodiments, the processor may be located outside of thepatient's body. For example, the processor 10 may be located togetherwith the display 15 and, optionally the alarm 20 within a common housing35, which can be worn, for example, on the patient's wrist or waist.

The display 15 may be an alphanumeric display, showing an absolute or arelative amount of the pain marker. In another embodiment, the display15 may be a color display changing colors when the amount of the painmarker or marker of degeneration is outside of the pre-determined range,such as, for example, the amount or the range of the pain marker ormarker of degeneration in a corresponding location taken from subjectswithout pain.

Optionally, the device of the present invention may comprise the alarm20 to alert the patient if the amount of the pain marker or marker ofdegeneration in a patient is outside of the amount or the range of thepain marker or marker of degeneration in a corresponding location takenfrom subjects without pain. The alarm 20 may alert the patient bydifferent stimuli or a combination thereof. For example, the alarm 20may be a light which flashes or changes color. Alternatively, the alarm20 may emit a sound signal. In another embodiment, the alarm 20 may emita tactile signal, such as, for example, vibration. In anotherembodiment, the alarm 20 may emit a light electric shock. In yet anotherembodiment, the alarm 20 may include a heating or cooling pad whichsends a thermal signal to the patient.

A person of ordinary skill will appreciate that the amount of the painmarker or marker of degeneration may be quantified outside of thesubject's body. Accordingly, in this embodiment, the sensing area 30 ofthe detector 5 can be used to collect a sample from the disc region, andthe processor 10 and the display 15 are not included in the device.Alternatively, the sensing area 30 may be used for initial reaction withthe pain marker or marker of degeneration, such as, for example,substrate enzymatic reaction, antigen-antibody binding or anotherbinding assay and then quantification of the binding or enzymaticactivity may be performed ex vivo. The quantification of the pain markeror marker of degeneration could be done visually, or by exposure of theprobe to a solution, light source, x-ray source, gas, or other reagentto allow the detection.

In another embodiment, the processor 10 may send information to adevice, such as a pump, that provides a treatment to alter directly orindirectly the level of the detected marker or otherwise mitigate pain.

Markers

The instant disclosure describes different markers to diagnose pain andsign of disc degeneration and methods of detection of these markers. Aperson of ordinary skill in the art will recognize that pain may bediagnosed by quantification of selected chemical or biologicalcompounds, selected physical activities or selected physical stimuli andany combination thereof. The suitable non-limiting examples of physicalactivities or stimuli are pressure, thermal changes, pH, electricalactivity, water content, tissue density, absorption of electromagneticradiation, and any combination thereof.

This invention describes pain marker or marker of degeneration selectedfrom the group consisting of markers of neuronal, immune, vascular ormatrix elements, and any combination thereof.

Suitable examples of marker of neuronal elements include neurotoxins,for example, a dye, neuronal growth factors including nerve growthfactor, brain-derived growth factor, glial-derived growth factor,neurotrophin-3, neurotrophin-4, insulin-growth factor, fibroblast growthfactor and leukemia inhibitory factor, neuronal extra-cellular matrixcomponents including chondroitin sulfate proteglycans, netrins,semaphorins and myelin/oligodendrocyte growth inhibitors, such as Nogo,MAG and Omgp, neuronal adhesion molecules, such as NCAM, N-cadherins andintegrins, a cytoskeletal component of the growth cone andneurofilaments, agents that can interact with neuronal elementsincluding camphor, menthol, piperine, mustard oil, curcumin and eugenoland vanilloid receptor agonists and antagonists such as8-Methyl-N-vanillyl-trans-6-nonenamide (Capsaicin); Z-Capsaicin;Gingerol; Zingerone; 8-Methyl-N-vanillylnonanamide (Dihydrocapsaicin);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-daphnetoxin,20-(4-hydroxy-5-iodo-3-methoxybenzeneacetate) (5′-Iodoresiniferatoxin);(+)-Isovelleral; N-Vannilyloleoylamide (Olvanil); Phorbol12,13-dinonanoate 20-homovanillate; Resiniferatoxin;N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);2,3,4-Trihydroxy-6-methyl-5-[(2E,6E)-3,7,11-trimethyl-2,6,10-dodecatrienyl]benzaldehyde (Scutigeral);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-20-(4-hydroxybenzeneacetate)daphnetoxin (Tinyatoxin); capsaicin synthetics; and capsaicinderivatives and vanilloid receptor antagonist such asN-[2-(4-Chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamide(Capsazepine);[N-(4-Hydroxy-3-methoxyphenyl)methyl]-5Z,8Z,11Z,14Z-eicosatetraenamide](Arvanil); N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791) and5′-iodoresiniferatoxin, agents that can interact with neuronal ligandsand related receptors and molecules involved in trafficking, breakdownand recycling of neuronal ligands and neuronal receptors includingnociceptors, adrenergic, cholinergic, glutamate, GABA, serotonine,somatostatin opioids, ATP, Na⁺, K⁺, Ca²⁺, cannabinoids, Substance P andneuropeptide receptors including substance P and neuropeptides,acetylcholine, glutamate, GABA, serotonine, somatostatin, adrenaline,epinephrine, botulinum toxin, anti-convulsants, anesthetics, analgesics,opioids and cannabinoids, agents that can detect neuronal supportingcells or glial cells including astrocyte, oligodendrocyte, microglia andSchawnn cells markers such as Glial Fibrillary Acidic Protein, S-100,CR3 receptor and glial toxins such as fluorocitrate and any combinationsthereof.

Suitable examples of markers of immune elements of an immune elementinclude inflammation-linked cytokines, chemokines, potassium ions,lactic acid, neuropeptides and several polypeptide amines, bradykinin,histamine, prostaglandins ligands and related receptors and moleculesinvolved in trafficking, breakdown and recycling of ligands andreceptors including, without limitation IL-1, IL-6, IL-8, TNF-alpha, INFand IFN regulatory factor 3, Toll-like receptor and adaptor moleculesand agents that can interact with immune elements such as steroids,nonsteroidal anti-inflammatory drugs, COX inhibitors, NFkB modulators,nitric oxide synthetase and any combinations thereof.

Suitable examples of marker of vascular elements include angiogenic andantiangiogenic ligands and related receptors and molecules involved intrafficking, breakdown and recycling of ligands and receptors includinganti-angiogenic steroid or an angiostatic steroid, such as anecortaveacetate or triamcinolone acetonide, growth factor or cytokine such asvascular growth factor, fibroblast-growth factor, angiopoietins, pigmentepithelium-derived factor or α-IFN, vascular extra-cellular matrixcomponents including matrix metalloproteinase and modulators includingmarimastat, a vascular cell adhesion molecule such as a cadherin orintegrin, marker of vascular elements such as Von Willebrand factor andany combinations thereof.

Suitable examples of marker of matrix elements include tissue density ofthe disc or elements adjacent to the disc, for example, the normallygel-like nucleus pulposus, level and type of extracellular matrixcomponents such as proteoglycans, metalloproteinases and proteolyticenzymes, keratin sulfate, collagen, nitric oxide, free radicals,fibronectin fragments, and any combinations thereof.

Suitable examples of markers of neuronal, immune, vascular or matrixelementss that have been modified so they can be used with imagingtechniques including radiography, MRI, PET or SPECT, CT, luminescence,include the markers of neuronal, immune, vascular or matrix elementslinked to a radioisotope including ¹⁸F, ³H, ¹²⁴I, ¹²⁵I, ¹³¹I, ³⁵S, ¹⁴C,¹¹C or a fluorescent or luminescent molecules. Suitable examples ofradiolabeled markers include modified markers that can bind opioidreceptors such as ¹⁸F1-(3-fluoropropyl)-4-(4-cyanophenoxymethyl)piperidine or [(18)F]FPS or¹⁸F-FPS, ³H and ¹¹C carfentanil, ³H pentazocine, ³H-1,3di-ortho-tolylguanidine, (+)-p-¹¹C methylvesamicol, ¹¹C SA4503, ¹¹CSA5845, N-[¹⁸F]4′-fluorobenzylpiperidin-4yl-(2-fluorophenyl) acetamide([¹⁸F]FBFPA),3-(4-chlorobenzyl)-8-[¹¹C]methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one,¹¹C nemonapride, radiolabeled pentazocine, progesterone, SKF 10,047, DuP734, BD1008, SM-21 haloperidol, DTG, progesterone, modified markers thatcan bind to glutamate receptor ³H MK801,1-amino-3-[¹⁸F]fluoromethyl-5-methyl-adamantane, ¹¹C-ABP688, modifiedmarkers that can detect cholinergic receptor and transmission such as[¹⁸F]fluoroethoxy-benzovesamicol, 2-[¹⁸F]F-A-85380, [¹¹C]-mecamylamine,5-(3′-fluoropropyl)-3-(2-(S)-pyrrolidinylmethoxy)pyridine (nifrolidine),5-(2-(4-pyridinyl)vinyl)-6-chloro-3-(1-methyl-2-(S)-pyrrolidinylmethoxy)pyridine, [N-¹¹C-methyl]-benztropine and neuronal glial marker that canbind to the peripheral benzodiazepine receptor including ¹¹C-R-PK11195,a radiolabeled antibody such as a radiolabeled antibody that can bindthe marker of matrix element, keratin sulfate.

In yet another embodiment, the pain marker or marker of degenerationcomprises an activator for example a provocative or reactive substancethat enables the detection of the neuronal, vascular, immune or markerof matrix element. The activator may be administered separately, prior,concurrently or following administration of the pain marker or marker ofdegeneration.

Suitable non-limiting examples of activators include agents that canactivate neuronal receptors including nociceptors, vanilloid,bradykinin, adrenergic, cholinergic, glutamate, GABA, serotonine,somatostatin opioid, ATP, Na⁺, K⁺, Ca²⁺, cannabinoid, Substance P andneuropeptide receptors. Exemplary activators include substance P andneuropeptides, bradykinin, acetylcholine, glutamate, adrenaline,epinephrine, opioid and derivates, capsaicin and derivates, camphor,menthol, piperine, mustard oil, curcumin, eugenol, neurotoxin,activators of blood flow and pro-inflammatory molecules includinghistamine and pro-inflammatory cytokines.

In other embodiments of the invention, the pain marker or marker ofdegeneration may comprise an activator of physical nature, such as, forexample, pressure, electrical activity, thermal and pH changes, and anycombination thereof.

In yet another embodiment, the activator may be administered locally viaa catheter positioned at or near the intervertebral disc. In thisembodiment, the catheter has a proximal end and a distal end, theproximal end having an opening to deliver the provocative or reactivesubstance in situ, the distal end being fluidly connected to apharmaceutical delivery pump. In one embodiment of the invention, thedelivery pump is operably connected to a reservoir which may optionallybe included in the device of the present invention. The catheter may bepositioned via a minimally invasive procedure, such as, for example, byaccessing a blood vessel adjacent or supplying blood to the site of thepathological condition.

Pressure.

One of the pain marker or marker of degeneration of this invention ispressure. Use of pressure as the pain marker is especially advantageousif the sensing area 30 of the detector 5 is placed inside theintervertebral disc. There are multiple ways to measure and transmit theinformation about the amount of pressure from the detector 5 to theprocessor 10. In one embodiment, the detector can measure the amount ofpressure by detecting the strain induced on a sensor element, i.e.,transducer. The sensor converts the strain into an electrical signal bymeasuring the resistance of the strained element, such as is done inpiezoresistive-based sensors, or the change in vibrational frequency ofthat element, such as is done in resonance-based sensors.Pressure-sensitive membranes and circuitry associated therewith isdescribed in details in the U.S. Pat. Nos. 7,007,551 and 6,959,608,entire contents of which are incorporated into the instant disclosure byreference.

Temperature.

Inflammation leading to pain is often accompanied by localized increasein temperature. Thus, detection of temperature increase within the discregion may be used as an marker of immune element or an activator fordiagnosis and monitoring of the pain generator(s) and disc degenerationassociated with axial pain with or without radiculopathy. Accordingly,in one embodiment, the sensing area 30 comprises a temperature probe.

The design and the methods of making and using a temperature probe, theprocessing circuits associated therewith are explained in details inmultiple patent and non-patent publications, such as, for example, U.S.Pat. No. 6,175,752, which is incorporated herein by reference in itsentirety. Briefly, two probe leads are connected to each other by atemperature-dependent element made from a material or a composition witha temperature-dependent characteristic. The probe leads are typicallyformed using a metal, an alloy, a semimetal, such as graphite, adegenerate or highly doped semiconductor, or a small-band gapsemiconductor. Examples of suitable materials include gold, silver,ruthenium oxide, titanium nitride, titanium dioxide, indium doped tinoxide, tin doped indium oxide, or graphite. The temperature-dependentelement is typically made using a fine trace of the same conductivematerial as the probe leads, or another material such as a carbon ink, acarbon fiber, or platinum, which has a temperature-dependentcharacteristic, such as resistance, that provides atemperature-dependent signal when a voltage source is attached to thetwo probe leads. The temperature-dependent characteristic of thetemperature-dependent element may either increase or decrease withtemperature. Preferably, the temperature dependence of thecharacteristic of the temperature-dependent element is approximatelylinear with temperature over the expected range of physiologicaltemperatures.

One exemplary method for forming this particular temperature probeincludes forming the two spaced-apart channels and then filling themwith the metallic or alloyed conductive material. Next, thecross-channel is formed and then filled with the desired material. Thematerial in the cross-channel overlaps with the conductive material ineach of the two spaced-apart channels to form an electrical connection.

Proteinaceous Pain Markers.

Another set of pain marker or marker of degeneration utilized in oneaspect of this invention are using antibodies directed against aneuronal, vascular, immune and matrix element, for example, antibodiesagainst inflammatory-linked cytokines, neurotransmitters, neuropeptides,growth factors, chemokines, nitric oxide, nitric oxide synthetase,acetylcholine, acetylcholine esterase, bradykinin, histamine,prostaglandins and receptors, cellular adhesion molecules, cytoskeletonelements, extra-cellular matrix components and any combinations thereof.A suitable antibody-based method of detection of chemical substances isdescribed, for example, in the U.S. Pat. No. 7,003,184, which isincorporated herein by reference in its entirety. In this embodiment,the sensing area 30 of the detector 5 comprises an optical fiber, atleast one optically responsive detector, such as, for example, FBGsensor, and a coating located adjacent to the optical fiber. In oneembodiment of the invention, the coating is located peripherally of theoptical fiber. As described in the above-referenced patent publication,the coating is made from a material, which is capable of changing itsvolume in response to a presence or an amount of the pain marker ormarker of degeneration. The change in the volume of the coating altersat least one optical property of the optical fiber. A suitable coatingmaterial is a hydrogel. Different types of hydrogels may be used withthe current invention. For example, the swelling behavior of polymer gelnetworks is governed not only by the affinity of polymer chains forsolvents, but also by the cross-linking density, (see for example M.Shibayama and T. Tanaka, “Volume phase transitions and related phenomenaof polymer gels,” in Advances in Polymer Science, vol. 109, SpringerVerlag, 1993). The cross-linking density controls the elastic restoringforce. Affecting the elastic restoring force in turn affects theequilibrium swelling volume of the gel network.

Polymer gel networks responsive to specific biochemicals can also beprepared by application of stimuli-sensitive complex formation atcross-linking points in the gel network, e.g. application ofantigen-antibody binding at cross-linking points.

One way to synthesize such materials is to use the well-knownpolyacrylamide gel system (PAAm) and including the functionalizedrecognition molecule in the cross-link-co-polymerization reaction. Anexample of this is described by T Miyata et al., “A reversiblyantigen-responsive hydrogel,” Nature, vol. 399, pp. 766-769, 1999, whoused the polyacrylamide gel system to conjugate IgG antibody to preparean antigen-responsive gel. Competitive binding of the free antigen(analyte) break the antigen-antibody (receptor) cross-link, therebyreducing the cross-linking density and triggering a change in gelvolume.

Further, the sensor area may comprise a detector housing comprising anarea of a porous material. Such design will protect the coating and theoptical fiber and at the same time provide an access of the pain markeror marker of degeneration to the coating.

The antibodies to the pain markers, markers of degeneration or fragmentsthereof can be produced by methods well known to those skilled in theart. For example, monoclonal antibodies to the pain markers can beproduced by generation of hybridomas in accordance with known methods.Hybridomas formed in this manner are then screened using standardmethods, such as ELISA, to identify one or more hybridomas that producean antibody that specifically binds to a neuronal, vascular, immune ormatrix element or a part thereof.

As an alternative to preparing monoclonal antibody-secreting hybridomas,a monoclonal antibody to the pain markers, markers of degeneration orfragments thereof, may be identified and isolated by screening arecombinant combinatorial immunoglobulin library (e.g., an antibodyphage display library) to thereby isolate immunoglobulin library membersthat bind to the pain markers or fragments thereof. Kits for generatingand screening phage display libraries are commercially available from,e.g., Dyax Corp. (Cambridge, Mass.) and Maxim Biotech (South SanFrancisco, Calif.). Additionally, examples of methods and reagentsparticularly amenable for use in generating and screening antibodydisplay libraries can be found in the literature.

Polyclonal sera and antibodies may be produced by immunizing a suitablesubject, such as a rabbit, with the pain markers, markers ofdegeneration or fragments thereof (preferably mammalian; more preferablyhuman). The antibody titer in the immunized subject may be monitoredover time by standard techniques, such as with ELISA, using immobilizedmarker protein. If desired, the antibody molecules directed against thepain markers or fragments thereof may be isolated from the subject orculture media and further purified by well-known techniques, such asprotein A chromatography, to obtain an IgG fraction, or by affinitychromatography.

Fragments of antibodies to the pain markers, markers of degeneration orfragments thereof may be produced by cleavage of the antibodies inaccordance with methods well known in the art. For example,immunologically active F(ab′) and F(ab′)₂ fragments may be generated bytreating the antibodies with an enzyme such as pepsin. Additionally,chimeric, humanized, and single-chain antibodies to the pain marker, themarker of degeneration or at least a part thereof, comprising both humanand nonhuman portions, may be produced using standard recombinant DNAtechniques. Humanized antibodies to the neuronal, vascular, immune ormatrix markers or fragments thereof may also be produced usingtransgenic mice that are incapable of expressing endogenousimmunoglobulin heavy and light chain genes, but which can express humanheavy and light chain genes.

Acetylcholine.

Electrochemistry is one of suitable methods of detection forneurotransmitters such as catecholamines (e.g., dopamine andepinephrine) and serotonin, as it can be used to determine the lowendogenous neurotransmitter concentrations in brain microdialysates andother in vivo samples. Acetylcholine and choline lack an electrophore,so in one embodiment an indirect method is used, based on the productsof enzyme reactions.

A suitable non-limiting process of acetylcholine measurement is providedby Bioanalytical Systems (West Lafayette, Ind.). In that process,acetylcholine is first converted to choline by acetylcholinesterase, andcholine reacts with choline oxidase to form hydrogen peroxide, which iselectrochemically active. Accordingly, in one embodiment, the sensingarea 30 comprises a peroxidase enzyme working electrode, which includessources of acetylcholinesterase and choline oxidase. Using theperoxidase enzyme working electrode for the detection of hydrogenperoxide, basal acetylcholine (in the absence of inhibitors) can beobserved, as the wired electrode allows measurement at a potential wherebackground is minimal, thereby lowering the detection limit.

In another embodiment, detection of acetylcholine may be performedthrough a mechanism similar to the one for detection of theproteinaceous pain markers. In addition to, or instead of, an antibodyrecognizing acetylcholine, the coating may comprise acetylcholinesteraseand choline oxidase. In this embodiment, hydrogen peroxide will createelectrical and/or pH change in the coating. Accordingly, a suitablematerial for the coating on this embodiment of the invention would be amaterial responding (e.g., swelling) to changes in pH or electricalactivities.

Diagnostic Imaging

In another embodiment, the pain markers or markers of degeneration maybe directly visualized by labeling the marker of neuronal, immune,vascular or matrix elements with a label. The label may be aradioisotopes or fluorochrome that can be visualized by imagingtechniques including radiography, MRI, PET, SPECT, CT or fluoroscopy.For example radioisotope can include ¹⁸F, ³H, ¹²⁴I, ¹²⁵I, ¹³¹I, ³⁵S,¹⁴C, ¹¹C. Suitable example of radiolabeled markers of neuronal opioidreceptors using ¹⁸F1-(3-fluoropropyl)-4-(4-cyanophenoxymethyl)piperidine or [(18)F]FPS or¹⁸F-FPS, ³H and ¹¹C carfentanil, ³H pentazocine, ³H-1,3di-ortho-tolylguanidine, (+)-p-¹¹C methylvesamicol, ¹¹C SA4503, ¹¹CSA5845, N-[¹⁸F]4′-fluorobenzylpiperidin-4yl-(2-fluorophenyl) acetamide([¹⁸F]FBFPA),3-(4-chlorobenzyl)-8-[¹¹C]methoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one,¹¹C nemonapride, radiolabeled pentazocine, progesterone, SKF 10,047,DuP734, BD1008, SM-21 haloperidol, DTG, progesterone, modified markersthat can bind to glutamate receptor ³H MK801,1-amino-3-[¹⁸F]fluoromethyl-5-methyl-adamantane, ¹¹C-ABP688,radiolabeled markers of neuronal cholinergic receptor and transmissionsuch as [18F]fluoroethoxy-benzovesamicol, 2-[¹⁸F]F-A-85380,[¹¹C]-mecamylamine,5-(3′-fluoropropyl)-3-(2-(S)-pyrrolidinylmethoxy)pyridine (nifrolidine),5-(2-(4-pyridinyl)vinyl)-6-chloro-3-(1-methyl-2-(S)-pyrrolidinylmethoxy)pyridine, [N-¹¹C-methyl]-benztropine and radiolabeled marker of neuronalglial element such as peripheral benzodiazepine receptor including¹¹C-R-PK11195, a radiolabeled antibody such as a radiolabeled antibodythat can bind the marker of matrix element, keratin sulfate.

The label may be a radioisotope, such as, for example, ¹⁸F, ³H, ¹²⁴I,¹²⁵I, ¹³¹I, ³⁵S, and ¹⁴C. These labels may be attached to a marker, forexample an antibody, by using a chelating agent, such as EDTA or DTPA,and detected by gamma counter, scintillation counter, PET scanning, orautoradiography. Other methods of labeling the marker are described, forexample, in the U.S. Pat. App. No. 2005/0118165 and in Hunter et al.,Nature 194:495 (1962); G. S. David et al., Biochemistry 13:1014-1021(1974); D. Pain et al., J Immunol Meth 40:219-230 (1981); and H. Nygren,J. Histochem Cytochem. 30:407 (1982), all of which are incorporated byreference herein.

In other embodiments, the label is a fluorescent label. Commonfluorescent labels include fluorescein, dansyl, phycoerythryn,phycocyanin, allophycocyanin, o-phtaldehyde, and fluorescamine. In yetother embodiments, the label may comprise a fluorescence-emitting metalsuch as, for example, ¹⁵²Eu⁺ or other lantanoids. Thefluorescence-emitting metals can be attached to the marker, such as, forexample, an antibody by using metal-chelating groups such as EDTA orDTPA.

In another embodiment, since radioisotopes may have a limited half-life,labeling of a pain marker or marker of degeneration may be performedwithin a few hours prior to administration.

A person of ordinary skill in the art will appreciate that the marker,activator and therapeutic agent may be administered to the subject viamultiple methods. Among these methods are an intravenous administration,an intramuscular administration, an intrathecal administration, asubcutaneous administration, an epidural administration, an intra-discaladministration, a parenteral administration, an oral administration, adirect application onto or adjacent to a site of the pathologicalcondition, and any combinations thereof. A person of ordinary skill inthe art will select the appropriate method based on the nature of thepain marker or marker of degeneration.

In yet another embodiment, the marker, the activator and the therapeuticcompound may be administered locally via a catheter positioned at oradjacent to the intervertebral disc. In this embodiment, the catheterhas a proximal end and a distal end, the proximal end having an openingto deliver the marker in situ, the distal end being fluidly connected toa pharmaceutical delivery pump. In one embodiment of the invention, thedelivery pump is operably connected to a reservoir which may optionallybe included in the device of the present invention. The catheter may bepositioned via a minimally invasive procedure, such as, for example, byaccessing a blood vessel adjacent or supplying blood to the site of thepathological condition.

In another embodiment, the activator may be administered in combinationwith the marker or separately, prior, concurrently or followingadministration of the pain marker or marker of degeneration.

In another embodiment, the therapeutic agent may be administered incombination with the marker or separately, prior, concurrently orfollowing administration of the pain marker or marker of degeneration.

In yet another embodiment, the labeled marker may be implanted into thesubject, for example, in forms of a pump or a depot. A suitablenon-limiting design of a depot implant is discussed in details in aco-pending U.S. patent application Ser. No. 11/403,733 entitled DrugDepot Implant Designs And Methods Of Implantation, filed on Apr. 13,2006. For example, the pump or depot can be implanted to monitorimprovement of treated disc or element adjacent to the disc or monitorpotential pain generators linked to axial pain with or withoutradiculopathy.

In another aspect, the invention provides methods for diagnosis of axialpain with or without radiculopathy. In one embodiment, the methodcomprises determining an amount of a pain marker or marker ofdegeneration within the disc region. The amount of the pain marker ormarker of degeneration can be measured by any method described above. Insome embodiments, such as, for example, where the activator is used,and/or where the marker or labeled marker is used, the method mayfurther comprise a step of administering the activator and/or the markeror labeled marker, respectively, and the amount of the pain marker ormarker of degeneration (i.e., the test amount) is measured indirectly.The test amount is then compared to a normal amount or range. The testamount outside of the normal amount or range (e.g., the test amountwhich is significantly different (i.e., p<0.05)) is used to present orpotential future pain generator(s) associated with axial pain with orwithout radiculopathy.

Normal Ranges of the Pain Markers.

Normal ranges of at least some of the pain markers or marker ofdegeneration have been disclosed previously. For example, it has beenshown that intervertebral discs of healthy humans do not expressdetectable levels of TGF-β1, IL-6, or IL6-R, as measured byimmunohistochemistry. Specchia et al., Eur. Spine J. 11:145-151 (2002).Accordingly, detection of these markers by the detector 5 will indicatea likelihood of pain or disc degeneration. Another example is the matrixelement, keratin sulfate, which is not found in degeneration but nothealthy disc in a rat model of disc degeneration. Kairemo K J A et al.,J Nucl Med (2001). Levels of other pain markers and markers ofdegeneration may be obtained from such sources as, for example, freshcadavers (recently deceased subjects) or healthy volunteers. If thesubject is not human, the data on normal values of the pain markers andmarkers of degeneration may be obtained from lab animals of the samespecies as the subject.

In yet another aspect, the invention comprises a method of testing anability of a treatment comprising administering a therapeutic compoundto reduce axial pain with or without radiculopathy or a likelihoodthereof in a future, the method comprising: determining an amount of apain marker or marker of degeneration within the disc region at a firsttime, said first time is prior to a first administration of thetherapeutic compound; determining an amount of the pain marker or markerof degeneration within the disc region at a second, later time; whereby|M₁−N|>|M₂−N| indicates that the treatment is efficient in reducingaxial pain with or without radiculopathy or the likelihood thereof inthe future, wherein M₁ equals to the amount of the pain marker or markerof degeneration measured at the first time; M₂ equals to the amount ofthe pain marker or marker of degeneration measured at the second time;and N equals to the normal range or amount of the pain marker or markerof degeneration (i.e., an amount or range from an individual(s) knownnot to suffer from axial pain with or without radiculopathy).

A person of ordinary skill in the art will recognize that the thresholdfor pain may vary between different patients. Accordingly, the resultsof the diagnosing the axial pain, the testing of the potentialcandidates to relieve the axial pain, and/or the monitoring of the axialpain may be correlated with the pain measurements according totechniques of pain assessment known in the art. Such correlation enablethe practitioner to choose the course of treatment which better fits theneeds of the patient. The techniques of pain assessment include, withoutlimitation, VAS, Oswestri, and SF-36 Questionnaires. Alternatively, thepain may be assessed based on disc height, disc hydration level, type IIcollagen level, proteoglycan levels, and any combination of thetechniques disclosed above.

In some embodiments, such as, for example, where the activator is used,and/or where marker or labeled marker is used, the method may furthercomprise a step of administering the activator and/or the marker orlabeled marker, respectively, and the amount of the pain marker ormarker of degeneration (i.e., the test amount) is measured indirectly.

Another aspect of invention provides multiple kits. In one embodiment,the invention provides a kit comprising a composition for diagnosing acurrent or potential pain generator of an axial pain condition with orwithout associated arm or leg radicular pain comprising a pain marker ormarker of a degeneration that can be detected by at least one imagingtechnique, and a set of instructions for efficient and safe use of thekit. In another embodiment, the kit further comprises instructions onhow to modify the marker for imaging purposes. In another embodiment,the kit comprises materials necessary to access an amount or an activityof a pain marker or marker of a degeneration from a sample extractedfrom a disc or an area adjacent to the disc by any method describedabove. Preferably, the method is selected from the group consisting ofan ELISA, an enzymatic reaction, an antibody-antigen assay, and otherbinding assays where the signal is detected by calorimetric,fluorescence, luminescence or radiometric modalities. In yet anotherembodiment the kit may provide an activator. A person skilled in the artwill undoubtedly appreciate that the set of instruction may be providedin any medium, including, without limitations, printed, audio and videorecorded, and electronic.

A person of ordinary skill in the art will undoubtedly understand that“treatment” includes all parameters of alleviating axial pain with orwithout radiculopathy. Without limitation, such parameters include theidentity of the therapeutic compound or a combination of the therapeuticcompounds used to alleviate the pain or reduced the signs ofdegeneration, a dosage of the therapeutic compound or the combination ofthe therapeutic compound, a frequency of administering the therapeuticcompound or the combination of the therapeutic compounds, formulationsof the therapeutic compound or the combination of the therapeuticcompounds, and a method of administering the therapeutic compound or thecombination of the therapeutic compounds.

Since increased neuronal and/or vascular extensions in an intervertebraldisc are likely to result in the axial pain with or withoutradiculopathy, the therapeutic compounds, which can retard the growth ofsuch neuronal and/or vascular extensions, or repel these extensions,thus preventing a formation thereof, or destroy the neuronal andvascular extension already formed in the intervertebral disc, are amongthe therapeutic compounds which can be tested to ensure the optimalcompositions and modes of administration of these therapeutic compoundsfor treatment of axial pain with or without radiculopathy.

Suitable non-limiting examples of such therapeutic compounds include,without limitation, natural neurotoxins; neurotoxins comprising ammoniaor cyanide; bisbenzimide; trypan blue; brilliant blue; methylene blue;indocyanine green; ruthenium red; quinoline yellow; saporin; Rho kinaseactivators; camphor; menthol; piperine; mustard oil; eugenol; curcumin;8-Methyl-N-vanillyl-trans-6-nonenamide (Capsaicin); Z-Capsaicin;Gingerol; Zingerone; 8-Methyl-N-vanillylnonanamide (Dihydrocapsaicin);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-daphnetoxin,20-(4-hydroxy-5-iodo-3-methoxybenzeneacetate) (5′-Iodoresiniferatoxin);(+)-Isovelleral; N-Vannilyloleoylamide (Olvanil); Phorbol12,13-dinonanoate 20-homovanillate; Resiniferatoxin;N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);2,3,4-Trihydroxy-6-methyl-5-[(2E,6E)-3,7,11-trimethyl-2,6,10-dodecatrienyl]benzaldehyde (Scutigeral);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-20-(4-hydroxybenzeneacetate)daphnetoxin(Tinyatoxin); capsaicin synthetics; capsaicin derivatives; botulinumtoxin; anti-convulsants; anesthetics; analgesics; opioids; cannabinoids;N-[2-(4-Chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamide(Capsazepine);[N-(4-Hydroxy-3-methoxyphenyl)methyl]-5Z,8Z,11Z,14Z-eicosatetraenamide](Arvanil); N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);5′-iodoresiniferatoxin; steroids; nonsteroidal anti-inflammatorycompounds; COX inhibitors; modulators of TNF-alpha or IL-1 cytokines orreceptors; NFkB modulators; minocyclin, fluorocitrate, anti-oxidants,free radical chelators, and any combination thereof. These therapeuticcompounds, formulations, and the methods of use for treatment ofdiscogenic pain are described in details in an co-pending U.S. patentapplication Ser. No. 11/414,689 entitled Biological Removal Of VascularAnd/Or Neuronal Extensions From A Degenerating Disc, filed on Apr. 28,2006, which is incorporated into the instant disclosure by reference inits entirety.

All patent and non-patent publications cited in this disclosure areincorporated herein in to the extent as if each of those patent andnon-patent publications was incorporated herein by reference in itsentirety. Further, even though the invention herein has been describedwith reference to particular examples and embodiments, it is to beunderstood that these examples and embodiments are merely illustrativeof the principles and applications of the present invention. It istherefore to be understood that numerous modifications may be made tothe illustrative embodiments and that other arrangements may be devisedwithout departing from the spirit and scope of the present invention asdefined by the following claims.

1. A kit for diagnosing a pain generator of an axial pain condition withor without radiculopathy comprising: materials necessary to access anamount or an activity of a pain marker or a marker of degeneration froma sample extracted from a disc or an area adjacent to the disc by amethod selected from the group consisting of an ELISA, an enzymaticreaction, an antibody-antigen assay, and other binding assays where thesignal is detected by calorimetric, fluorescence, luminescence orradiometric modalities, a set of instructions.
 2. The kit of claim 1further comprising an activator.
 3. The kit of claim 2, wherein the setof instructions comprises instructions on how to administer theactivator.
 4. The kit of claim 1 further comprising a device to extractthe sample.
 5. The kit of claim 4 wherein the device is a needle havinga diameter of 18 G or less and wherein the device is capable ofretrieving a sample of up to about 1000 μl.
 6. The kit of claim 1wherein the pain marker or the marker of degeneration is selected fromthe group consisting of markers of neuronal, immune, vascular and matrixelements, and any combination thereof.
 7. The kit of claim 6 wherein thepain marker or the marker of degeneration is selected from the groupconsisting of the markers of the neuronal elements.
 8. The kit of claim7, wherein the pain marker or the marker of the degeneration can detecta molecule released by the neuronal elements.
 9. The kit of claim 7,wherein the pain marker or the marker of degeneration is capable ofbinding a neuronal receptor.
 10. The kit of claim 9 wherein the neuronalreceptor is an opioid receptor.
 11. The kit of claim 9, wherein theneuronal receptor is a sigma opioid receptor.
 12. The kit of claim 6,wherein the pain marker or the marker of degeneration is selected fromthe group consisting of the markers of the vascular elements.
 13. Thekit of claim 12, wherein the pain marker or the marker of degenerationcan detect an angiogenic agent.
 14. The kit of claim 12, wherein thepain marker or the marker of degeneration can detect a molecule releasedby the vascular elements.
 15. The kit of claim 6, wherein the painmarker or the marker of degeneration is selected from the groupconsisting of the markers of the immune elements.
 16. The kit of claim15, wherein the pain marker or the marker of degeneration can detect apro-inflammatory agent.
 17. The kit of claim 16, wherein the immuneelements are selected from the group consisting of inflammatory-linkedcytokines.
 18. The kit of claim 6, wherein the pain marker or the markerof degeneration is selected from the group consisting of the markers ofthe matrix elements.
 19. The kit of claim 1, wherein the pain marker orthe marker of degeneration can detect an extracellular component. 20.The kit of claim 2, wherein the activator is administered by a methodselected from the group consisting of an intravenous administration, anintramuscular administration, an intrathecal administration, asubcutaneous administration, an epidural administration, a parenteraladministration, an oral administration, an intra-discal administration,a direct application onto or adjacent to a site of a pathologicalcondition, and any combinations thereof.
 21. The kit of claim 20,wherein the activator is administered by the direct application onto oradjacent to the site of the pathological condition.
 22. A method ofdiagnosing a pain generator or a potential pain generator of an axialpain conditions which may be associated with radiculopathy in a patientcomprising: determining an amount of a pain marker or a marker ofdegeneration in a location inside of or adjacent to an intervertebraldisc; comparing the amount of the pain marker or the marker ofdegeneration from the patient with a normal range of the pain marker orthe marker of degeneration in a corresponding location, wherein theamount of the pain marker or the marker of degeneration outside of thenormal range indicates a current or a potential axial pain conditionswhich may be associated with radiculopathy.
 23. The method of claim 22wherein the step of determining the amount of the pain marker or themarker of degeneration is performed intraoperatively.
 24. The method ofclaim 22 wherein the step of determining the amount of the pain markeror the marker of degeneration is performed in conjunction with anadministration of a therapeutic compound at least partially effective inrelieving pain or decreasing an amount or an activity of the pain markeror the marker of degeneration.
 25. The method of claim 24, wherein thetherapeutic compound is selected from the group consisting ofneurotoxin, botulinum toxin, ammonia or cyanide; bisbenzimide; trypanblue; brilliant blue; methylene blue; indocyanine green; ruthenium red;quinoline yellow; saporin; Rho kinase activators; camphor; menthol;piperine; mustard oil; eugenol; curcumin;8-Methyl-N-vanillyl-trans-6-nonenamide (Capsaicin); Z-Capsaicin;Gingerol; Zingerone; 8-Methyl-N-vanillylnonanamide (Dihydrocapsaicin);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-daphnetoxin,20-(4-hydroxy-5-iodo-3-methoxybenzeneacetate) (5′-Iodoresiniferatoxin);(+)-Isovelleral; N-Vannilyloleoylamide (Olvanil); Phorbol12,13-dinonanoate 20-homovanillate; Resiniferatoxin;N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);2,3,4-Trihydroxy-6-methyl-5-[(2E,6E)-3,7,11-trimethyl-2,6,10-dodecatrienyl]benzaldehyde (Scutigeral);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-20-(4-hydroxybenzeneacetate)daphnetoxin(Tinyatoxin); capsaicin synthetics; capsaicin derivatives; botulinumtoxin; anti-convulsants; anesthetics; analgesics; opioids; cannabinoids;N-[2-(4-Chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamide(Capsazepine);[N-(4-Hydroxy-3-methoxyphenyl)methyl]-5Z,8Z,11Z,14Z-eicosatetraenamide](Arvanil); N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);5′-iodoresiniferatoxin; anti-inflammatory compounds, free radicalchelators and any combination thereof.
 26. A method of testing anability of a treatment comprising administering a therapeutic compoundto reduce an amount of a pain marker or a marker of degeneration orprophylacticly treat axial pain conditions which may be associated witharm or leg radicular pain, the method comprising: determining the amountof the pain marker or the marker of degeneration within a disc or anarea adjacent to the disc at a first time, said first time is prior to afirst administration of the therapeutic compound; determining an amountof the pain marker or the marker of degeneration within the disc or thearea adjacent to the disc at a second, later time; whereby |M₁−N|>|M₂−N|indicates that the treatment is efficient in reducing the current orpotential axial pain conditions which may be associated with arm or legradicular pain, wherein M₁ equals to the amount of the pain marker orthe marker of degeneration measured at the first time; M₂ equals to theamount of the pain marker or the marker of degeneration measured at thesecond time; and N equals to a normal range or amount of the pain markeror the marker of degeneration.
 27. The method of claim 26, wherein thetherapeutic compound is selected from the group consisting ofneurotoxin, botulinum toxin, ammonia or cyanide; bisbenzimide; trypanblue; brilliant blue; methylene blue; indocyanine green; ruthenium red;quinoline yellow; saporin; Rho kinase activators; camphor; menthol;piperine; mustard oil; eugenol; curcumin;8-Methyl-N-vanillyl-trans-6-nonenamide (Capsaicin); Z-Capsaicin;Gingerol; Zingerone; 8-Methyl-N-vanillylnonanamide (Dihydrocapsaicin);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-daphnetoxin,20-(4-hydroxy-5-iodo-3-methoxybenzeneacetate) (5′-Iodoresiniferatoxin);(+)-Isovelleral; N-Vannilyloleoylamide (Olvanil); Phorbol12,13-dinonanoate 20-homovanillate; Resiniferatoxin;N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);2,3,4-Trihydroxy-6-methyl-5-[(2E,6E)-3,7,11-trimethyl-2,6,10-dodecatrienyl]benzaldehyde (Scutigeral);6,7-Deepoxy-6,7-didehydro-5-deoxy-21-dephenyl-21-(phenylmethyl)-20-(4-hydroxybenzeneacetate)daphnetoxin(Tinyatoxin); capsaicin synthetics; capsaicin derivatives; botulinumtoxin; anti-convulsants; anesthetics; analgesics; opioids; cannabinoids;N-[2-(4-Chlorophenyl)ethyl]-1,3,4,5-tetrahydro-7,8-dihydroxy-2H-2-benzazepine-2-carbothioamide(Capsazepine);[N-(4-Hydroxy-3-methoxyphenyl)methyl]-5Z,8Z,11Z,14Z-eicosatetraenamide](Arvanil); N-(3-Methoxyphenyl)-4-chlorocinnamide (SB-366791);5′-iodoresiniferatoxin; anti-inflammatory compounds, free radicalchelators and any combination thereof.
 28. A method of monitoring anaxial pain conditions which may be associated with radiculopathy in apatient comprising: determining an amount of a pain marker or a markerof degeneration in a location inside of or adjacent to an intervertebraldisc at a first time; determining an amount of the pain marker or themarker of degeneration in the location inside of or adjacent to theintervertebral disc at a second, later time; whereby |M₁−N|<|M₂−N|indicates that the axial pain conditions which may be associated withradiculopathy or the likelihood thereof in the future has increased, and|M₁−N|>|M₂−N| indicates that the axial pain conditions which may beassociated with radiculopathy or the likelihood thereof in the futurehas decreased, wherein M₁ equals to the amount of the pain marker or themarker of degeneration measured at the first time; M₂ equals to theamount of the pain marker or the marker of degeneration measured at thesecond time; and N equals to a normal range or amount of the pain markeror the marker of degeneration.
 29. The method of any of the claims 22,26 and 28, wherein the pain marker or the marker of degeneration isselected from the group consisting of markers of neuronal, immune,vascular, and matrix elements, and any combination thereof.
 30. Themethod of claim 22, 26 or 28 wherein the pain marker or the marker ofdegeneration is selected from the group consisting of an antibodydirected against nerve growth factor, brain-derived growth factor,glial-derived growth factor, neurotrophin-3, neurotrophin-4,insulin-growth factor, fibroblast growth factor and leukemia inhibitoryfactor, chondroitin sulfate proteglycans, substance P, neuropeptides,acetylcholine, glutamate, GABA, serotonine, somatostatin, adrenaline,epinephrine, TNF-alpha, NFkB, INF, IL-1, IL-6 neuropeptides, bradykinin,histamine, prostaglandins ligands and receptors; angiogenic andantiangiogenic agents, Toll-like receptor and adaptor molecules,vascular growth factor, fibroblast-growth factor, angiopoietins andpigment epithelium-derived factor ligands and receptors,metalloproteinase, cadherin and integrin, Von Willebrand factor,proteoglycans, proteolytic enzymes, keratin sulfate, collagen,acetylcholinesterase, fibronectin fragments, any variants, and anycombinations thereof.
 31. The method of any of the claims 22, 26 and 28,further comprising the step of administering an activator.
 32. Themethod of claim 31, wherein the activator is administered by a methodselected from the group consisting of an intravenous administration, anintramuscular administration, an intrathecal administration, asubcutaneous administration, an epidural administration, a parenteraladministration, an oral administration, an intra-discal administration,a direct application onto or adjacent to a site of the pathologicalcondition, and any combinations thereof.
 33. The method of claim 32,wherein the activator is administered by the direct application onto oradjacent to the site of the pathological condition.
 34. The method ofclaim 31, wherein the activator is selected from the group consisting ofsubstance P, neuropeptides, bradykinin, acetylcholine, glutamate,adrenaline, epinephrine, opioid and derivates, capsaicin and derivates,camphor, menthol, piperine, mustard oil, curcumin, eugenol, neurotoxin,activators of blood flow and pro-inflammatory molecules.
 35. The methodof claim 34, wherein the proinflammatory molecules are selected from thegroup consisting of histamine and pro-inflammatory cytokines.
 36. Themethod of claim 31, wherein the activator is a physical agent selectedfrom the group consisting of light, pressure, electrical activity,thermal and pH changes, and any combination thereof.